If x + y = 1, then x3 + y3 + 3xy - 1 =?
In an alloy of German silver the ratio of copper to zinc was 19 : 6 while that of nickel to zinc was 7 : 4. The ratio of copper to zinc to nickel in the alloy was:
Group the following figures into three classes based on their identical properties
1,3,9; 2,4,6; 5,7,8
1,5,9; 2,4,6; 3,5,7
1,2,5; 3,6,7; 4,8,9;
1,5,9; 2,3,6; 4,5,7;